A Review of the NIOSH Roadmap for Research on Asbestos Fibers and Other Elongate Mineral Particles (2009)

NIOSH states, “The purpose of the Roadmap is to outline a research agenda that will guide the development of specific research programs to be conducted by NIOSH and others, both within and across disciplines, to provide answers to current scientific questions, reduce scientific uncertainties, and provide a sound scientific foundation for future policy development” (NIOSH, 2009a, p. i). The NIOSH Roadmap is divided into three major sections: “Review of Current Issues,” “Framework for Research,” and “The Path Forward.” The review of current issues (62 pages) describes in detail the state of the science, including terminology issues; trends in usage, exposures, and asbestos-related disease; sampling and analytical issues; and physical and chemical properties related to toxicity. The framework for research (24 pages) presents the research goals and objectives and acknowledges that the framework is not all encompassing. The Roadmap states, “Within each of the goals and objectives laid out in this framework, a more detailed research program will have to be developed.… Any research project that is undertaken should ensure that the results can be interpreted and applied within the context of other studies in the overall program and lead to outcomes useful for decision-making and policy-setting” (NIOSH, 2009a, p. 65). The path forward (2 pages) describes the next steps in implementing the Roadmap including identifying specific research to be conducted, prioritizing research to achieve the proposed goals, and building partnerships to see the research to fruition.

The remainder of this chapter considers the process used to develop the Roadmap, considers how the Roadmap fits into a broader research strategy intended to implement the research, and examines and discusses the organization and key components of the Roadmap. Chapter 3 ad-

dresses the major scientific issues of the draft Roadmap including an evaluation of the state of the science, the rationale for proposed research, and research needs.

NIOSH released its draft Roadmap document Asbestos and Other Mineral Fibers: A Roadmap for Scientific Research in February 2007 and posted it on the public docket. In May 2007, NIOSH held a public meeting on the Roadmap at which a number of presentations were made on proposed changes to the document (NIOSH, 2009b). The Roadmap was also submitted to a panel of expert reviewers. The draft document was revised in response to reviewer comments and was released in June 2008 (NIOSH, 2009c). The June version was further revised in response to public review. Table 2-1 summarizes this timeline. The January 2009 version entitled Revised Draft NIOSH Current Intelligence Bulletin. Asbestos Fibers and Other Elongated Mineral Particles: State of the Science and Roadmap for Research (NIOSH, 2009a) is the version that was reviewed by this committee and is referred to throughout this report as “the Roadmap.”

The committee recognizes the considerable effort and expertise that went into developing the Roadmap. Further, NIOSH has sought input from a number of stakeholders and expert peer reviewers. The process has been open and iterative and has provided several opportunities for comments by interested parties.

The challenge in developing and implementing the research program outlined in the Roadmap lies in the interagency and interdisciplinary nature of the research questions. Because NIOSH is not the only federal agency involved in efforts on asbestos and numerous stakeholders are interested in these issues, implementation of the Roadmap will involve many other entities. Having wider authorship of the Roadmap beyond NIOSH would have been challenging. Another possibility might have been to have had an external independent organization develop the Roadmap as was done for the Environmental Protection Agency’s (EPA’s) research strategy on airborne particulate matter, a congressionally mandated effort that is discussed below (NRC, 1998). Having said this, the committee believes that the multiple opportunities to comment on the Roadmap have engaged a wide range of stakeholders and the

important work ahead to implement the Roadmap will have to involve the relevant federal agencies, organizations, associations, and interested parties.

A roadmap is defined as “a detailed plan to guide progress toward a goal” (Merriam-Webster, 2009). The NIOSH Roadmap comports with this definition and takes an important step toward articulating a research

agenda for examining the potential toxicities of all elongate mineral particles. In thinking about the key components of a roadmap, the committee first considered the broader picture of how a research agenda is implemented and then examined other examples of research strategies and the ways in which these strategies incorporate a research roadmap (NRC, 1998, 2007, 2009).

In 1998 the National Research Council produced Research Priorities for Airborne Particulate Matter (NRC, 1998). This report (along with three subsequent companion reports) presented a policy-relevant research strategy for addressing uncertainties surrounding the setting of the national ambient air quality standards for particulate matter. The report presented a conceptual framework for an integrated national program of particulate matter research, identified the most important research priorities, and described the recommended short-term and long-term timing and estimated costs of such research in an integrated strategy (NRC, 1998). This series of reports had substantial positive impact on EPA’s long-term research planning, the coordinated implementation of intramural and extramural research efforts to address knowledge gaps, and congressional funding for the particulate matter research program.

In 2007 the NRC report A Review of the Ocean Research Priorities Plan and Implementation Strategy reviewed a plan that established the first coordinated national interagency research planning effort to support ocean science. The NRC report was supportive of the research plan but found that it lacked some important elements including a vision for ocean research in the next decade, a ranking of either long-term or near-term priorities, a discussion of the level of needed funding, an implementation strategy, and metrics by which the plan would be evaluated.

The NRC conducted a review of the federal strategy for environmental, health, and safety research on nanotechnology and outlined the following important elements of a research strategy in its report, Review of the Federal Strategy for Nanotechnology-Related Environmental, Health, and Safety Research (NRC, 2009):

• Vision, or statement of purpose. What is the ultimate purpose of conducting the research?

• Goals. What specific research goals should be achieved?

• Evaluation of the state of science.

• Roadmap. What is the plan of action to achieve the stated goals? What are the specific objectives, and when do they need to be achieved? How will other efforts and initiatives be leveraged, in-

cluding industry and international initiatives? How will the roadmap be adjusted in light of new knowledge? What is the time required for the plan to become effective?

• Evaluation. How will progress be measured, and who will be responsible for measuring it? Are there measurable milestones that can be evaluated against a clear timeline?

• Review. How will the strategy be revised in light of new findings, to ensure that it remains responsive to the overarching vision and goals?

• Resources. Are there sufficient resources to achieve the stated goals? If not, what are the plans to obtain new resources or to leverage other initiatives to achieve the goals?

• Mechanisms. What are the most effective approaches to achieving the stated goals? How will exploratory and targeted research be used? What will the balance be between principal investigator-driven and goal-driven research and between intramural and extramural research programs? How will research efforts be coordinated to ensure a coherent approach to achieving the stated goals? What provisions are there for enabling interdisciplinary research that crosses established funding and agency boundaries?

• Accountability. How will stakeholders participate in the process of developing and evaluating a research strategy? Who will be accountable for progress toward stated goals? Who will be responsible for disseminating information generated within the research strategy and ensuring its use in raising awareness and making decisions?

As outlined above, the NIOSH Roadmap is one part of a larger research strategy. The committee urges NIOSH to consider working with other agencies and organizations to develop a strategy to ensure that the Roadmap will move forward with adequate funding and accountability.

The current Roadmap suggests that the next steps will involve parsing out the activities to five independent study groups. Although this is a common approach, the committee believes that the nature of the issues requires combined attention from all disciplines. Sampling and characterization issues should be the concern of toxicologists and epidemiologists as well as mineralogists. Toxicology, epidemiology, and risk assessment overlap in interests and goals. Moving away from discipline-specific review groups would go a long way toward achieving the integrated understanding that is necessary. The committee urges considera-

tion of an interdisciplinary and comprehensive research strategy to ensure the implementation of this research (Chapter 4).

The focus of this report is on one part of the research strategy—the research roadmap. In drawing from the examples above and the committee’s expertise with similar documents, the committee has concluded that the NIOSH Roadmap needs to be strengthened to clearly address the following key components:

• Overarching vision

• Rationale for the endeavor—in this case, the public and occupational health rationale

• Research goals

• Research framework—the systematic plan for conducting the research

Each of these components is discussed below in terms of how it is currently presented and how it could be improved in the Roadmap.

The fundamental research questions discussed in the Roadmap revolve around how to assess the relative health hazards of exposures to the full spectrum of elongate mineral particles. The Roadmap needs a clearly stated vision that points toward research that will rank or define the range of potential health hazards of exposures to a spectrum of elongate mineral particles and help determine the influence of size, shape, and other physical and chemical characteristics of elongate mineral particles on human health. This research would identify which elongate mineral particles, or what characteristics of those particles, should be included in recommendations to protect workers and others from hazardous occupational and environmental exposures. For example, what research should be conducted if confronted with exposures to previously untested mineral particles at a mine site or in a construction workplace? What procedures should be undertaken to define the inherent toxicity of the elongate mineral particles, to rank their toxicity against those of par-

ticles having known potential for causing harm, and to define the exposure levels of concern?

A roadmap for developing an extensive body of scientific work provides the rationale for the research in order to help justify the needed resource investments. The committee strongly supports NIOSH in its development of the Roadmap but considers that the Roadmap, in addition to providing the scientific rationale, should clearly articulate the influence that ongoing and future research can have on improving public and occupational health. For example, although the Roadmap provides data on the health effects of asbestos exposure and their related latency, it would be helpful if it also included a discussion of exposures to other elongate mineral particles, the numbers of workers potentially affected, and the extent of environmental exposures that might impact public health. This information would help clarify and solidify the purpose of the Roadmap and provide a justification for funding and interagency collaboration.

The NIOSH Roadmap clearly describes the research program’s goals (Box 2-1). However, the goals are presented as independent “silos” of effort to address toxicology, mineralogy, epidemiology, and analytical methods separately, rather than emphasizing the interdependent, interdisciplinary nature of this research. Greater integration of the goals across disciplines is necessary to ensure that the research results can be drawn together and to foster the needed collaboration among scientists and across agencies. Further, the goals have to be structured so as to drive the research program. The current goals are written broadly. An effort is needed to make the goals more focused and explicit so that they inform the systematic exploration of the potential toxicity of various types of elongate mineral particles related to specific physical, chemical, and surface properties and other factors that might affect human health.

As discussed in detail in Chapters 3 and 4, NIOSH has done a commendable job of describing the current state of knowledge. However, the Roadmap lacks a vision of how to use the science in a prospective way to assess potential hazards or a plan for developing the ability to do so. A standardized stepwise process for assessing the nature and extent of potential health hazards of inhaled elongate mineral particles is needed to address concerns that arise when a previously unstudied exposure situation (e.g., as occurred at Libby, Montana) is encountered. The same systematic approach would be useful for characterizing and ranking hazards from materials encountered in currently known exposure situations.

A generalized systematic framework for characterizing exposure and hazards from inhaled materials is readily conceived, and such stepwise testing frameworks have been developed for other materials (e.g., ILSI Risk Science Institute Working Group, 2005). A step-by-step approach would allow evaluation of the toxicities of elongate mineral particles across the spectrum of potential human exposures to identify which fraction of the spectrum is most problematic for human health. Although selection of the specific procedures and tests to be used remains, at least in part, a knowledge gap to be addressed by research, the Roadmap should explicitly point to the need for developing such a generalized framework. The framework should be presented to fit into the broader scope of research on airborne particulates.

The framework of tiered testing would begin with the identification and physical and chemical characterization and identification of the mineral(s) involved in the exposure and proceed through increasingly complex biological screening steps until the biological hazard was judged to be adequately classified.

ILSI Risk Science Institute Working Group. 2005. Testing of fibrous particles: Short-term assays and strategies. Inhalation Toxicology 17:20.

Merriam-Webster. 2009. Merriam-Webster online dictionary. http://www.merriam-webster.com/dictionary/road+map (accessed April 21, 2009).

NIOSH (National Institute for Occupational Safety and Health). 2009a. Revised draft. NIOSH current intelligence bulletin. Asbestos fibers and other elongated mineral particles: State of the science and roadmap for research. January 2009. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. http://www.cdc.gov/niosh/docket/pdfs/NIOSH-099b/099B-040109AsbestosNAReviewDoc.pdf (a`ccessed September 18, 2009).

NIOSH. 2009b. NIOSH Docket Number 099: Asbestos and other mineral fibers: A roadmap for scientific research. http://www.cdc.gov/niosh/docket/NIOSHdocket0099.html (accessed September 10, 2009).

NIOSH. 2009c. NIOSH Docket Number 099A: Current intelligence bulletin: Asbestos fibers and other elongated mineral particles: State of the science and roadmap for research. http://www.cdc.gov/niosh/docket/NIOSHdocket0099A.html (accessed September 10, 2009).

NRC (National Research Council). 1998. Research priorities for airborne particulate matter. I. Immediate priorities and long-range research portfolio. Washington, DC: National Academy Press.

NRC. 2007. A review of the ocean research priorities plan and implementation strategy. Washington, DC: The National Academies Press.

NRC. 2009. Review of the federal strategy for nanotechnology-related environmental, health, and safety research. Washington, DC: The National Academies Press.